* XLEN=16 redefines FPR "full width" operations to full [IEEE FP16](https://en.wikipedia.org/wiki/Half-precision_floating-point_format) and leaves
"half width" UNDEFINED (there is no IEEE FP8).
* XLEN=8 redefines FPR "full width" operations to [BF16 (bfloat16)](https://en.wikipedia.org/wiki/Bfloat16_floating-point_format) and leaves
* XLEN=16 redefines FPR "full width" operations to full [IEEE FP16](https://en.wikipedia.org/wiki/Half-precision_floating-point_format) and leaves
"half width" UNDEFINED (there is no IEEE FP8).
* XLEN=8 redefines FPR "full width" operations to [BF16 (bfloat16)](https://en.wikipedia.org/wiki/Bfloat16_floating-point_format) and leaves